Documentation/spi/spidev_test.c:83:5: warning: no previous prototype for 'unespcape' [-Wmissing-prototypes]

fix spelling too.
Acked-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>